In the making of hollow blown plastic articles such as containers, it has heretofore been suggested that labels be held in one or more of the mold sections by vacuum so that when the parison is blown outwardly into conformity with the cavity, the label becomes adhered or bonded to the article.
The molds are often provided in a plurality of sets of partible molds in a predetermined array and, in order to deliver the labels, a plurality of magazines are provided, one for each mold half, and an associated plurality of pick-up and delivery devices are provided to function to remove labels from the magazines and deliver them to one or both of the mold halves of each set.
As set forth in U.S. Pat. No. 4,636,166, having a common assignee with the present application, an apparatus is provided wherein labels are successively removed from a label magazine and positioned in an array which corresponds in spacing to the spacing of the sets of molds. The labels are then simultaneously moved in the array from the first position to a second position within the open partible molds and deposited in the molds. The apparatus comprises a magazine for supporting labels in a stack and an endless belt transfer device positioned adjacent the magazine. The belt is indexed in predetermined spaces corresponding to the spaces of the array of molds. A label pick-up device removes a label from the magazine and deposits it on the conveyor so that the spacing between the labels on the endless transfer conveyor corresponds to the spacing between the sets of molds. Another label deposit device removes the labels simultaneously from the endless transfer conveyor and delivers them between the open partible molds.
Where labels are to be cut from a roll of labels, problems arise because the free end of labels tends to move so that when a label is cut from the roll, the cut may not be square. These conditions are aggravated when the labels are made of plastic or plastic laminated film.
In U.S. Pat. No. 4,680,000, there is disclosed a method and apparatus for applying labels in the molds of a plastic blow molding machine of the type wherein a plurality of sets of molds are mounted on a wheel rotatable about a horizontal axis and the molds are moved toward and away from one another to enclose a parison and the parison is then blown to the confines of the cavity between the mold sections. In this patent, the method of delivery comprises removing labels successively from one or more magazines, depositing the labels on an endless conveyor which transports the labels to a position adjacent an open mold and laterally transferring the labels from the conveyor to a position within the molds such that when a mold closes about a plastic parison and the parison is blown, the labels become adhered to the blown plastic bottle.
The use of magazines inherently produces problems. Among these are the cost of magazines, the need to replenish the supply of labels in the magazines and the space required about the container forming machine. In addition, when plastic or foam labels are being handled, they are difficult to stack and handle for placement in the magazines. If the labels are cut from a web and stacked it is difficult to ascertain whether they are in proper registry. If the shape of the plastic or foam label is complex, the magazines are more complex. After being formed, the plastic or foam labels must be handled in batches or stacked and are not easily handled.
In co-pending application Ser. No. 063,643 filed June 22, 1987 now U.S. Pat. No. 4,853,169, there is disclosed a method comprising providing labels on a roll of labels, successively die cutting the labels from the web of the roll and simultaneously delivering each label directly to an endless vacuum conveyor, indexing the endless vacuum conveyor to provide an array of labels on the conveyor which corresponds in spacing to the spacing of the array of molds, engaging the array of labels on the conveyor and removing them from the conveyor and depositing the array of labels in the array of molds.
Among the objectives of the present invention are to provide a method and apparatus which results in more accurate placement of the labels on a vacuum transfer conveyor; which permits more careful control of the accuracy of the configuration of the labels; which permits labels of various configurations to be used; and wherein the orientation of the labels with respect to the vacuum transfer conveyor is greatly facilitated; and wherein the apparatus for receiving labels and delivering them to a conveyor functions efficiently and accurately such that it may be utilized with either die cut labels or labels removed from a magazine.
In accordance with the invention, the method and, apparatus provides for each label to be die cut directly onto vacuum pads which are in position for receiving the labels after which the vacuum pads are moved without substantially changing the orientation of the labels directly onto a vacuum transfer conveyor which is thereafter indexed to form an array of labels for delivery in an array to the molds.